51430642 has 4 divisors (see below), whose sum is σ = 77145966. Its totient is φ = 25715320.

The previous prime is 51430637. The next prime is 51430657. The reversal of 51430642 is 24603415.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24603415 = 5 ⋅4920683.

It can be written as a sum of positive squares in only one way, i.e., 31708161 + 19722481 = 5631^2 + 4441^2 .

It is a super-2 number, since 2×51430642² = 5290221873064328, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12857659 + ... + 12857662.

Almost surely, 2^51430642 is an apocalyptic number.

51430642 is a deficient number, since it is larger than the sum of its proper divisors (25715324).

51430642 is a wasteful number, since it uses less digits than its factorization.

51430642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25715323.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 51430642 is about 7171.5160182489. The cubic root of 51430642 is about 371.8838472297.

The spelling of 51430642 in words is "fifty-one million, four hundred thirty thousand, six hundred forty-two".